Combination changing mechanism for padlocks



April 15, 1958 H. c. MILLER 2,830,447

COMBINATION CHANGING MECHANISM FOR PADLOCKS Filed Sept. 12. 1956 2 hegets-Sheet 1 ll 3175C; |"\$'(71'I1 V40 W H 4 w I 14 gm 7 L A; INVENTOR ATTORNEYS V April 15, 1958 H. c. MILLER 2,830,447

COMBINATION CHANGING MECHANISM FOR PADLOCKS Filed Sept. 12, 1956 2 Sheets-Sheet 2 INVENTOR ATTORNEYS United States Patent 70 COIVIBINATION CHANGING MECHANISM FOR PADLOCKS Harry C. Miller, Rochester, N. Y. Application September 12, 1956, Serial No. 609,439

Claims. (Cl. 70 319) The present invention relates in general to combination resetting means for combination locks, and more particularly to combination locks of the exposed shackle pad key from externally of the lock housing through an opening usually provided in the rear cover plate of the housing and into openings in the tumblers which are aligned with the key opening in the rear cover plate when the tumblers are in a predetermined position.

The tumblers are conventionally supplied with a cam rotatably supported on an outer annular disc portion of each tumbler having a square opening for reception of a combination changing key by which the cam is rotated. This cam has a flattened peripheral portion positioned relative to a cam follower locking lever pivoted on the annular disc portion and intereonnectig the annular disc portion with a hub member causing the lever to be rotated through its biasing spring to disconnect the disc and hub portions when the cam is rotated to bring the flat into engagement with the follower lever.

The insertion of the combination changing key into the openings provided therefor in the tumblers effects a release of the outer annular disc portion of the tumblers of conventional construction from their inner hub portion by which the tumblers are driven, so that the position of the inner hub portions of the tumblers relative to their outer annular disc portions may be reset to any desired combination by turning the dial and driving cam. Since padlocks of the type having exposed shackles are designed to he usually coupled through a hasp staple, the lock housing is exposed and freely available to inspection by persons seeking unauthorized admission to the enclosure protected by the padlock. In view of this condition, movement of the tumblers, or at least the rearmost tumbler in these conventional combinationlocks, may be observed through the combination changing key opening inrthe rear cover plate of the lock housing and persons having knowledge of the general structural features of this type of lock can fairly readily detect the combination of the lock by insertion of small pieces of material such as shim stock through the exposed combination changing key opening and thereby gain unauthorized admission to the locked enclosure.

An object of the present invention is the provision of a novel combination changing mechanism for combination padlocks which is manipulatable to expose the mechanism for actuation only when the padlock is in unlocked condition.

Another object of the present invention is the provision "ice of a novel combination changing mechanism for combinatoin adlocks-of the exposed shackle type wherein the usual combination changing key opening-in the cover a plate of the padlock is eliminated.

Another object of the present invention is the provision of a novel combination changing mechanism for combination padlocks of the exposed shackle type wherein the com bination changing mechanism is accessible to be ma nipulated only through one of the shackle-receiving sockets of the padlock casing.

Another object of the present invention is the provision access openings to the tumbler chamber for insertion of combination changing keys or tools are dispensed with' and the security ofthe lock is improved.

Other objects, advantages and capabilities of the present invention will become apparent from the followiing detail description, taken in conjunction with the accompanying drawing showing only a preferred embodiment of the invention.

In the drawing:

Figure 1 is a rear elevation of an exposed shackle combination padlock embodying the present invention, with the cover plate removed;

Figure 2 is a vertical longitudinal section view of the combination padlock, taken along the line 22 of Figure 1;

Figure 3 is a horizontal transverse section view of the padlock taken along the line 3-3 of Figure 1;

Figure 4 is an enlarged section view of the tumbler construction employed in the present invention, taken along the line 44 of Figure 3; and

Figure 5 is an exploded perspective view of the. slide plate and associated tumblers.

Figure 6 is a perspective view of the driving cam and a portion of the'fence.

Referring to the drawing wherein like referencechar acters designate corresponding parts throughout the several views, the structure embodying the preferred embodimentof the present invention comprises a combination padlock generally indicated at 10 having a lock casing 11 including a front wall 12, side walls 13, curved bottom wall 14 and top wall 15, all integrally formed with the front wall 12 to produce a rearwardly opening' body. The top wall 15 is formed with a pair of laterally spaced circular openings 16 located adjacent the side walls 13 for receiving the-legsof the usual U-shaped shackle 17 when the padlock is in locked condition. In accordance with conventional practice, one of the legs of the shackle 17 is slidably connected with the'casing 11 so as' to per,- mit reciprocal movement of the shackle while that leg remains continuously within the casing 11. The end of t the opposite leg of the shackle 17 when the shackle is shifted to its outermost position relative to the casing 11 clears the outer surface of the top wall 15, permitting the shackle to be rotated about the axis of the leg which is restrained within the casing 11. i

The padlock casing 11 is also provided with a removable rear cover plate 18 which is attached to the side, bottom and top walls of the lock casing in any suitable manner. lournalled in the front wall 12 of the padlock casing is an arbor 19 which has fixed on the front end thereof the usual dial 20 which is disposed in accordance with conventional practice in overlying relation to the front wall 12 of the padlock casing, the dial 20 being rotatable to turn the arbor 19 and thereby control movement of the usual tumblers. The arbor 19 supports a driving cam Patented Apr. 15, 1958 d end of thearbor. The driving cam 21 is provided with a driving pin 23 projecting from the direction of the tumblers.

A plurality of tumblers 24 are rotatably supported on atubular boss 25 integral with and projecting rearwardly from the front wall 12'of the padlock casing. The tubular boss 25 also serves as thebearing in which the arbor 19 rotates. The tumblers 24, which are preferably three in number, are substantially conventional in construction, and are provided with the usual outer annular rim portion 26 adapted to be rotatably adjusted or set'on inner annular hubs 27 to establish the combination'of thelock. The rearwardly facing side of. the. rearmost hub 27 is provided with the usual annulargroove 27' interrupted at on P tiQn y a stop shoulderto be engaged by the driving pin23 projecting into the annular groove upon rotation of the driving cam 21 and effect the usual lost motion driving connection between the driving cam '21 and the rearrnost tumbler 24. The several tumblers 24 are also provided with the usual lost-motion connectionbetween adjacent pairs of the tumbler hubs similar to that between the driving cam and the rearmost'tumbler hub. The outer annular rims 26 are each formed of a pair of annular plates 28 fixed together by means of rivets 29, the plates 28 having aligned peripheralrecesses 30 forming the tumbler gates. The periphery of each hub 27 is preferably formed between the plates 28 with teeth or serrations '31 which are adapted to be engaged by the correspondingly toothed end of a locking lever 32 disposed between each pair of plates 28 and pivotally supported thercbetween by means of the pivot pin 33. v

The lever 32 is actuated bya leafspring 34 connected at one end of the spring 34 to the toothed end of the lever to urge thetoothed endout of engagement with the toothed periphery of the hub 27. The other end of the leaf spring 34 is connected to a counterbalance member 35 fixed to the plates 28. The cam follower end 36 of lever 32 is biased by leaf spring 34 into engagement with a cam 37 rotatably supported between the plates 28. The cam 37 is provided with a fiat or relieved portion, to be rotated into engagement with thecam follower end the front face thereof in 36 of the lever 32 and allow thelever 32 to be pivoted under the influence of the leaf spring 34 and free the lever 32 from locking engagement with the'hub 27. In this condition, the hubs 27 are free to be turned relative to their associated outer annular thus 26 to establish the combination ofthe look. -When' the cam37is returned to the position illustrated in Figure 4, the lever 32 'will be shifted under the influence of the spring 34 to bring the toothed end thereof-into locking engagement with the toothed surface of the hub 27 and interlock the hubs 27 and the rims 26 against relative-rotation.

It has been the conventional practice heretofore to provide a rectangular opening in the cam 37 adapted to receiveacorrespondingly shaped combination-changing key which is inserted through all the earns 37 and an opening in the rear cover plate 18 of the padlock casing when thecams and cover plate opening are aligned. Upon rotation of the key, the release of the tumbler rim portions from the associated hub is effected to permit setting of the combination. A special cam construction is necessitated by the present invention wherein the usual combination changing key openings. are eliminated.

Tothis end, the cam v37 is provided with gear teeth 38 occupying a portion of therperipheral surface 'of the camt37. A plate 39 is slidablysupported for reciprocal movement along one of the sidewalls 13 of the padlock casing in a guide member 40 fixed to or formed integral with theside wall 13, and is provided with rack segments 41 corresponding in number to the tumblers 24. A guide shoulder 42 is formed along one edge of the slide plate 39 and, in cooperation with the rear 'cover plate 18, positions the plate 39 to maintain the rack segments 41 in reciprocative paths intercepted by the earns 37 of the tumblers 24 when the tumbler gates 30 are in a preselected position. Guide pins 43 projecting from the edge of the plate 39 opposite the shoulder 42 extend into a groove 44 in the cover plate 18 to limit the movement of the plate 39 to a rectilinear path.

The uppermost end of the slide plate 39 is provided with a shoulder formation 45 having a threaded socket 46 therein aligned with the short shackle leg accommodating socket 16. An adjusting screw 47 is rotatably supported,

in a supporting block 48 fixed to the front wall 12 of the casing and held against axial movement by means of a screw head 49 and a C-washer 50, and is threaded into the socket 46 of the slide pl-ate 39. The upper end of the adjusting screw 47 is slotted and lies exposed at the bottom of the socket 16 designed to receive the short leg of the shackle 17. The slotted head of the adjusting screw 47 is therefore exposed at the bottom of the short cycle leg socket '16 to be manipulated by a screw driver inserted therethrough when the lock is unlocked, the shackle 17 retracted to withdraw the short leg from its associated socket, and the shackle rotated about its long leg to clear the entrance of the socket.

The tumblers 24 cooperate with the fence member 51 which is mounted above the tumblers and is reciprocally slidable in suitable guideways 52 in the direction of the longitudinal medial axis of the padlock casing to bring the, lower portion of the fence member 51, which extends laterally over the width of all of the tumblers, into contact with the tumblers. A plurality of coil springs 53 are disposed in the guideways 52 and bear .upon projecting shoulders of the fence member 51 to urge the fence toward the top wall 15 ,of the padlock casing to a position wherein the lower portion of. the fence member 51 is out of contact with thetumblcrs. The fence member 51 is likewiseprovided with a depending leg 54 operatively associated with the driving cam 21. A pairof pivotally supported locking arms 55 having outwardly directed locking portions are carried on the fence member 51 and are positioned between fixed pins 56 on the front casing wall 12 extending into suitable notches in the locking arms to project the outwardly directed'locking portions into the notches 17 of the shackle 17 upon movement of the fence member 51 toward the top casing wall 15. The depending leg 54 of the fence member 51 is of mappropriate length to engage the periphery of the driving 'cam21 as the fence member 51 isshifted toward the driving cam immediately before the portion of the fence member extending across the tumbler peripheries engages the tumblers, so as to prevent engagement of the fence member 51 with the tumblers peripheries when the driving cam gate 22 is out of alignment with the depending leg 54.

The driving cam 21 and fence 51 are preferably so designed that the driving cam and dial 20 are free to rotate when the padlock is in locked condition with the fence 51 projected into the tumbler recesses 36 in order to adjust the tumbler hubs 27 to establish a new combination. As an example of construction which will permit this, the rear face of the driving cam 21 may be provided with an annular groove 57 concentric with the axis thereof which is spaced inwardly of the periphery of the cam 21 and provides a rearwardly projecting annular llange 53 at the periphery of the cam 21. A radial gateway 59 is formed through the flange 58 for accommodating the leg 540i the fence. The edge of the leg 54 of the fence 51 which faces the driving cam 21 is provided with a recess 60 which is complementary to the cross section of the flange 58 and is spaced above the lower end of the leg 54 a suflicient distance to define a nose 61 of appropriate shape to fit into the annular groove 57 and ride therein in underlying relation to the flange 58 when the gateway 59 is out of alignment with the leg 54. The relationship of'these parts is such that when the tumbler recesses 30 and the driving cam gateway 59 are aligned with the fence 51 and fence leg 54, the fence leg 54 will pass through the gateway 59 upon movement of the-fence toward thetumblers and the nose 61 and recess.60, willbe aligned with the annular groove *and'flan'g'e SS 'respec-:

receses 30. This construction is fully shown in my' co-' pending application Serial No. 548,699, filed November 23, 1955. p e

The operation of the above described preferred form of a combination padlock embodying the present invention is as follows:

Assuming the componentsto be in the relative positions illustrated in Figure l with the padlock in locked condition, the padlock is manipulated to release the shackle 17 for withdrawal from locked condition by manipulating the dial knob 20 to rotate thedriving cam 21 in clockwise and counterclockwise directions alternately for preselected number of revolutions, in accordance with conventional practice in the art, to align the peripheral recesses 30 of the tumblers 24 with the fence member 51 and the driving cam gateway 59 with the depending leg 54. The particular combination which must be manipulated by the operator is determined, of course, by the relative positions of the rim and hub portions 26 and 27 of the tumblers, as established by the previous adjustment of the combination. When the tumbler anddrivingcam gates are thus aligned with the fence member, the operator'may exert outward manual pressure on the shackle 17, which pivots'the'locking portions of the locking arms 55 about their fixed pivot pins 56 due to the camming force on the locking portions of the locking arms 55 produced by the inclined edges of the shackle notches 17'. This movement of the locking arms 55 shifts the fence member 51 to which the locking arms are pivoted in the direction of the tumblers and driving cam and against the resilient upward force exerted on'the fence member 51 by the springs 53. If the tumbler recesses 30 or driving cam gateway 59 are not aligned with the fence member 51 and leg 54, the periphery of the non-aligned tumbler or driving cam will intercept downward movement of the fence 51 or leg 54 and prevent sufficient movement of the fence to allow the locking arms 55 to pivot free of the shackle notches 17'. If the tumbler recesses 30 and driving cam gateway 59 are properly aligned to receive the fence member 51 and depending leg 54, the fence member 51 will be shifted downwardly sufiicient to free the locking arms 55 from the shackle notches 17 and permit withdrawal of the short leg of the shackle from its associated socket 16.

Upon rotation of the shackle 17 about the long leg thereof to position the shorter leg out of axial alignment with its associated socket, the slotted head of the adjusting screw 47 will be exposed to permit manipulation thereof by a screw driver blade inserted into theunoccupied socket 16. To change the combination, the'operator manipulates the screw driver to rotate the adjusting screw 47 through a preselected number ofturns to 'shift the rack segments 41 on the slide plate 39 threaded to the screw 47 to interdigitate the rack segments 41 with the gear teeth 38 of the tumbler releasing earns 37 and to rotate the cams 37 a sufficient distance to bring the flats thereof into engagement with the cam follower ends36 of the levers 32. This movement of the earns 37 permits the leaf springs 34 to shift the serrated ends of the lever 32 out of interlocking engagement with the serrations 31 on the tumbler hubs 27 so as to free the tumbler hubs 27 for rotation in response to rotation of the dial 20 and driving cam 21 while the tumbler rims 26. are held against rotation by the fence member 51. The dial 20 is then rotated alternately in clockwise and counterclockwise directions to establish the new combination. Upon completion of adjustment of the dial 20 and tumbler hubs 27 to establish the new combination, the screw driver is again inserted into the unoccupied socket 16, the adjusting screw 47 is rotated to return the slide plate 39 and rack segments 41 to their lowermost position illustrated in Figure 1 wherein they are out of engagement with the gear teeth 38 of the tumbler releasing cams 37. During this return movement ofthe slide plate 39, the cams 37 are rotated back to the normal position illustrated in Figure 4 wherein the tumbler rims26 are interlocked with the tumbler hubs 27. Upon removal of the screw driver from the unoccupied socket 16, the shackle 17 is rotated to dispose the shorter leg thereof. in alignment with its associated socket 16 and manual pressure is applied to urge the shackle toward the padlock casing to return the parts to locked condition.

The above-described mechanism for changing the combination of the tumblers 24 may also be employed with equal facility inga padlock whose construction corresponds substantially with that described above, but wherein a conventional type of driving cam is provided having a single peripheral recess therein for accommodating a depending leg of the fencehaving no recess in the'forwardly' facing edge thereof, such as the driving cam and fence construction illustrated in my, earlier Patent No. 2,673,457. In such a case, the lower end of the depending leg of the fence member projects into the peripheral recess in the driving cam when the driving cam recess and tumbler recesses are aligned with the fence. I

As the depending leg of thefence which is then seated in the driving cam peripheral recess restrains the driving cam against rotation, it isnecessary in the manipula; tion of such a padlock to return the shackle to closed or locked position after the adjusting screw 47 has been adjusted to shift the slideplate 39 in position to unlatch the tumbler rims 26 from their hubs 27. This returning of the shackle to locked condition elevates the fence member out of-contact with the driving cam and tumblers and' frees the driving cam and dial 20 for rotation. The tumbler recesses 30, however, will be restrained in alignment with the fence during manipulation of the dial and driving cam to adjust the tumbler hubs 27 relative to their rims 26, by virtue of the fact that the teethof the rack segments 41 will be interfitted with the gear teeth 38 of the cams 37 and the fiat cam follower ends 36 of the locking levers 32' will be resiliently forced by the leaf springs 34 into intimate abutment with the flats of the earns 37. The'locking levers 32 will, therefore, resiliently hold the cams 37 against rotation about their own axes and the interfitting of the rack segments 41 with the gear teeth 38 of the cams 37 carried by the tumbler rims 26 cooperate to restrain the tumbler rims against rotation during adjustment of the tumbler hubs,

27 when the hubs have been freed for adjustment relative to the. rims. Consequently, after the dial 20 has been manipulated in accordance with the new combi-- nation to adjustthe orientation of the tumbler hubs 27 relative to their rims 26, the peripheral recesses 30 in the tumbler rims 26 will still be in alignment with the. fence 51 to accommodate the fence when the same is shifted toward the tumblers upon exertion of outward manual pressure on the shackle.

While only one preferred embodiment of the invention has been specifically shown and described, it is'apparent that various modifications may be made in the invention without departing from the spirit and scope thereof, and it is desired, therefore, that only such limitations shall be placed thereon as are set forth in the appended claims.

I claim:

1. In a permutation lock, the combination with a plurality of tumblers each having a hub portion and an blers having a plurality of driving formations corre manner 7 pendin s n mb to a d t m e e dear-t ed byt aid reeiprocative member simultaneously along a path tansent a o h r r e of a m into driving e gagement with lthe peripheries of said cams for t t ling said cams in synchronism with each other to and from a position releasing said interlocking means from said holding condition, and means externally accessible for manipulation upon preselected conditioning of said lock for shifting said reciprocative means to and from said' releasing position. V a a t. V

2.. In a permutation lock, the combination with a lock casing and a pluralityof tumblers each having a hub portion and an annular peripherally recessed rim portion andinterlocking means for coupling the rim portions withtheir associated hub portions against relative displacement, of a cam rotatably supported on each of said rim portions fordecoupling said interlocking means from said hub portions to permit rotation of said hub portions independently of said rim portions in establishing the combination of said lock, said cams haying peripheral toothed sectors exposed adjacent the peripheries of said rim portions reciprocative rack means supported for movement along a path tangential to the toothedperipher ies of said cams into interdigitating relation with saidtoothed cam sectors of eacher said cams for rotating said cams in synchronismwith each other to andrfro m a position decoupling.saidrinterlocking means from said rom ac ommodati ss kctt ere o .i na a l o said casing la. plurality of rotatab e tumblers each having a hub portion jand, anannular peripherally recessed rim portiori and interlocking means on'said rim portions for coupling the same with said-hub portions against relative displacement; the improvement comprising a cam rotatably supported on each. of said rim portions adjacent the peripherjies thereof for decoupling said interlocking means for said hub portions to permit rotation of said hub portions independently of said rim portions in establishing the combination'of said lockga reciprocative member supported on said casing vfor movement therein along a path tangentialto the peripheries of saidcams and aligned with the axis of said socket andhaving projections thereon engagcable with the peripheries of each of said cams during movement of said reciprocative member for rotating said cams in syrichronism with each-other to and from a position decoupling said interlocking means from said hub portions, and adjusting means disposed at the base of said socket for axial movement upon rotation thereof by an r instrument inserted into said socket and intercoupling huh portions, and means accessible for manipulation through said lock casing upon preselected conditioning of said lock for shifting said reciprocativemeans to and from said decoupling position, a a

3. In an exposed shackle combination padlock including a padlock casing, a U-shaped shackle supported in said casing to permit complete withdrawal of oneshackle leg from an accommodating socket therefor in the wall of said casing, and a plurality of rotatable tumblers'each having a hub portion and an annular peripherally recessed rim portion and interlocking means on the rim portions for coupling the same with said hub portions against relative displacement; means for controlling said interlocking means comprising a cam rotatably supported,

on each of said rim portions for decoupling said interlocking means from said hub portions to permit rotation of saidthub portions independently of said rim portions in establishing the combination of said lock, cam; actuating means supported in said casing for moyement into driving engagement with the peripheries of each of said,

cams for rotating said cams in fsynchronism with each other to and from a position decoupling said interlockingmeans from said hub'portions, and "meansextending from said cam actuating means disposed at the base of said accommodatingsocket and accessible ,for manipulat tion by an instrument inserted into said socket only when said lock is in unlocked condition withtsaid one shackle leg withdrawn therefrom for shifting said cam actuating means to and from said decoupling position.

with said reciprocative member for shifting said reciprocaltive member to and from interlocking means decoupling position, said one shackle leg barring access to said adjusting means when said leg occupies said socket.

5. In an exposed shackle combination padlock includ ing a padlock casing having a socket therein, a reciprocaa tive U's haped shackle shiftable relative to said casing to permit complete withdrawal of one leg thereof from and out of alignment with saidsocket, and a plurality of rotatable tumblers each having a hub portion, an annular peripherally recessed rim portion, and a latch on said rim portionsengageable with the associated hub portions for interlocking said portions against relative rotation; theimprovement comprising a cam rotatably supported on each of said rim portions for decoupling said latches from said hub portions to permit rotation of said hub portions independently of said rim portions during establishment of the combination of said lock, said cams having peripherally'toothed sectors exposed adjacent the peripheries of said rim portions, a reciprocative member having rack means'projecting therefrom supported on said casing for movement therein along a path tangential to the toothed peripheries of saidcams and aligned with the axis of said socket for interdigitating said rack means with said toothed cam sectors of each of said cams to rotate said cams in 4. In an exposed shackle combination padlock including a padlock casing, a U-shaped shackle supported in said a casing to permit complete withdrawal of one shackle leg synchronism with each other to and from positions decoupling said latchesifrom said 'hub portions, an adjusting screw disposed at the base of said socket for shifting said reciprocative member along said path to and from latch decoupling positions'upon rotation of said screw by an instrument inserted: into said socket, said one shackle leg barring access to'said adjusting screw when said leg occupiessaid socket.

RefereucesC ited in the file of this patent UNITED STATES PATENTS Baum July 28, 1908 

